Heavy oil conversion with low coke formation



' Feb. 24, 1959 s. c. scHUMAN HEAVY OIL CONVERSION WITH LOW COKEFORMATION Filed Nov. 12. 1953 g sa]J JL-T-.Z

JE j INVENTOR.

`smv/@UR Lc. scHuMAN BY i AGENT United States Patenti@ rice N HEAVY OILCONVERSION WITH LOW COKE FORMATION Seymour C. Schuman, Titusville, N.J., assignor to Hydrocarbon Research, Inc., New York, N. Y., acorporation of New Jersey Application November 12, 1953, Serial No.391,582

10 Claims. (Cl. 208-107) This invention relates to the conversion ofheavy oils into more valuable products, more particularly, the inventionis directed to the conversion of hydrocarbon oils boiling above about700 F. and containing a substantial proportion of asphaltenes. o

A principal object of this invention is to convert vheavy hydrocarbonoils into valuable gaseous and liquid products with low coke formation.Further objects and advantages will be apparent from the descriptionwhich follows.

In accordance with the invention, heavy hydrocarbon oil is injected intoa high-velocity gaseous stream containing hydrogen and carrying insuspension a heated particulate carrier whereby the oil is convertedinto volatilized products and a carbonaceous deposit on the carrier. Theheavy oils for which the process is particularly adapted may derive frompetroleum, coal, tar sands and oil shale and are characterized asboiling essentially above about 700 F. and having a Ramsbottom carbonvalue (ASTM No. `D`52452T) of at least about 10 and very frequentlyabove 15. Such oils are generally highly aromatic and contain a largeproportion of asphaltenes and resinous compounds. To convert heavy oilsto lighter liquid and gaseous products with low carbon formation, it hasbeen found necessary to subject the oil in the presence of hydrogen to atemperature in therange of about 1200. to 1600 F., preferably 1300 to1500 F., for a period not exceeding about 3 seconds, preferably notexceeding about 1 second. C

The process employs a finely divided solid carrier, generally of a sizethat all passes through a Ll-mesh sieve and preferably at least about50% by weight thereof passes through a G-mesh sieve. The carrier, heatedto provide temperatures in the aforesaid conversion range when contactedby the heavy oil, is carried in suspension by a hydrogen-containinggasiform stream traveling at a Velocity of at least 10, preferably atleast 20, feet per second. Under these conditions, the carrier'particles travel with substantially the same velocity of the suspendinggasiform stream. Although the carrier particles may in some instancesexperience a little slippage relative to the gasiform stream, thevelocity of the particles will still be at least 70% of that of thegasiform stream.

It is a noteworthy feature of this invention that the conversion ofheavy hydrocarbons to more valuable products is carried out at lowhydrogen partial pressure and yet the formation of carbon is materiallycurtailed. Hydrogen partial pressures as low as about 35 p. s. i.(pounds per square inch) 'are effective in the process of thisinvention. The hydrogen partial pressure is preferably in the range of75` to`200 p. s. i. and generally does not exceed 400 p. s. i. Theprocess consumes considerable hydrogen in the conversion of heavy oils;for instance, a consumption of approximately 1000 standard cubic feet ofhydrogen per barrel of charge heavy oil is frequently encountered.

i The short-time, high-temperature conversion of heavy oils is carriedout with the carrier particles dispersed as 2,875,150 Patented Feb. 24,1959 a dilute phase in the suspending, high-velocity gasiform stream.Generally, the carrier loading does not exceed about 5 pounds per cubicfoot of suspending gas and often is in the range of about 1 to 2 poundsper cubic foot.

In the course of the hydrocarbon conversion, carbonaceous material isdeposited on the carrier particles. The thus fouled carrier, afterstripping absorbed heavy hydrocarbons therefrom, is subjected toregeneration. Advantageously, the fouled carrier is reacted with oxygenand steam at temperatures of at least about 1600 F., preferably in therange of 1700 to 2000 F. to yield regeneration product gases containinga substantial proportion of hydrogen. The regenerating gas contains apreponderance of steam and a minor proportion of highpurity oxygen, thelatter usually containing atleast about 90% by volume of oxygen andpreferably atleast 95% by volume of oxygen. Steam-to-oxygen volumeratios in the range of 1.5:1 to 5:1 are generally satisfactory forgenerating the required hydrogen. In many instances, the steam-to-oxygenvolume ratio is of the order of 2:1 to 3:1.

The particulate carrier employed in the process of this invention is anysolid material that will withstand the desired regeneration conditions,including a temperature above 1600 F., Without physically disintegratingor fusing, such as sand, quartz, alumina, magnesia, Zircon, beryl orbauxite. Absorptive carriers of the type disclosed in the copendingapplication of C. A. Johnson and S. C. Schuman, Serial No. 388,903,filed October 28, 1953, are preferred.

To describe and explain this invention more fully, reference is made tothe accompanying drawings where- 1n:

Figure 1 diagrammatically illustrates an apparatus adapted for carryingout the process of the invention; and

Figure Zis a diagrammatic vertical section of a hydrocrackerincorporating therein the process of this invention.

Referring now to Figure 1, finely divided. carrier, all passing throughan -mesh sieve, heated to a temperature of about 1750 F. in regenerator10 is passed through slide valve 12 into conversion conduit 14 where itis suspendedin a high-velocity gaseous stream containing hydrogen, whichis introduced into conduit 14 lat the point 16. Into the stream carryingthe heated carrier particles through conduit 14 at a velocity of about25 feet per second, a heavy residuurn is injected through feed line 18and valved branch line 20. Alternatively, the feed stock may be injectedinto conduit 14 through valved branch line Z2 or valved branch line 24depending upon whether a somewhat shorter or a somewhat longerconversion time is desired. The mixture of feed stock and carrierdispersed in the gaseous stream has a temperature in the range of 1300to` 1500 F. The stream discharges from conduit 14 into cyclone separator26 where the carrier particles now coated with carbonaceous matter areseparated from the gasiform stream containing the cracked hydrocarbons.The fouled carrier particles pass down from cyclone Z6 throughVstandpipe 28 into regenerator 10, while the gasiform efluent iswithdrawn through outlet 30 and sent to a conventional recovery systemwhich separates the products of conversion into desired fractions.

Steam and `oxygen are introduced into the lower pory tion of regenerator10 `by way of distributor 3. A small quantity of steam is injectedthrough tap 34 into the.

ofgabout"175.0 `to yeldsaregeneration product 'gas rich in hydrogen.While the :oxygen is substantially completely reacted in the lowerportion of regenerator 10, it is preferred to have a baille structure 38disposed at an intermediate'level in 'the ,iluidized mass of carrierwithin regenerator so as to curtail top-to-bottom mixing. The upperportion of the yiluidized bed which has a pseudo-liquid level 36provides va Zone in which the fouled catalyst discharging from standpipe28 is subjected to stripping to remove absorbed hydrocarbons from thefouled catalyst. While the regeneration product gases are very effectivefor stripping absorbed hydrocarbons from the fouled carrier, additionalgas, such assteam, may be introduced through distributor 40`particularly where it is desired to maintain a lower temperature in theportion of the fluidized mass above baffle structure 38. Thus, thefouledcarrier may besubjected to stripping ata ternperature `of about 1500F..above baille structure 33 and regenerated at a temperature of aboutl750 F. below battle structure 38. The regeneration product gases alongwith stripped hydrocarbons on emerging from the pseudoliquid level 36are withdrawn from regenerator 10 through outlet 42 and passed to aconventional recovery system to separate out the hydrocarbons from thenormally `gaseous components of that stream.

The suspending gas introduced into conduit 14 at the point .16 may bederived fromthe gaseous. stream leaving regenerator 10 at outlet 42. Itis also possible to recycle hydrogen-containinggas which isseparatedfrom the gasiforrn .etiluent withdrawn at outlet 30.

The apparatusof Figure 2 is essentially a hydrocracker as disclosedinthe copending application of J. A. Finneran,` Jr., and F. B.Grosselfnger, Serial No. 299,114, -led July 16, 1952, but modified toinclude the high-temperature, short-time cracking of a heavy recyclestock in accordance with this invention. Vessel 50 contains a tluidizedcarrier mass with a pseudo-liquid level 52. The upper portion of theuidized mass provides a primary cracking zone S4, .an intermediateportion containing packing bodies 56 like Raschig rings provides asecondary cracking zone 58 and the lower portion provides a regenerationzone .60. The packing bodies `56 are supported on .a perforated plate62. Thecharge stock is supplied to zone S4 through distributor 64 whileoxygen and steam for regeneration of the carrier particles areintroduced through distributor 66. The temperature of primarycrackingzone54 is generally maintained in the range of 85.0 .to 1100 F.,preferably in the range .of 900 to 1050 F., While regeneration zonef ismaintained at a ternperature of atleast 1.600'.F., preferably in therange of 1700 to 2000 F. Fouled carrier from zone 54 moves down throughpacked zone 58 countercurrent to regeneration product gases rich -inhydrogen and thus is subjected to stripping conditions at increasingtemperatures as the carrier approaches zone 60. The carrier stripped ofabsorbed hydrocarbons discharges from zone 58 into zone 60 where thecarbonaceous residue on the carrier particles is gasied by reaction withoxygen and steam.

Regenerated carrier flows from .zone 60 through opening 68 into.up-transport conduit 70. The flow of carrier through opening .68 may beyregulated by the position of valve body '7,2 mounted on tube 74 whichis moved vertically by turning threaded handle 76. The carrier isconveyed up through .conduit'70into zone 54 by a suspending gas,introduced through ,tube 74.

The total reaction eiiluent comprising the cracked hydrocarbons rand thehydrogenfcontaining regeneration product gases emerges frompseudo-liquid level 52, passes through cyclone separator 78 and Vflowsthrough outlet 80 .to .a conventionalrecoyery plant .to fractionate theliquid and gaseous products.

'Pursuant to .this invention, .theheaviest hydrocarbon fraction, boilingabove 700 F., .obtained from the total reaction e'luent isrecycledforurther conversion. This recycle stock is .injected throughline 82 and nozzle 84 into Yc`oriduit'70 whereit is dispersed ina'hi'gh-velocty gaseous stream containinghydrcgenand.conveyingregenerated carrier particles. The gas suppliedthrough tube 74 contains suicient hydrogen to provide in conduit 70 ahydrogen partial pressure in the range of 35 to 400 p. s. i. Thishydrogen-containing gas may be obtained by the fractionation of thetotalgasiform effluent leaving vessel 50 through outlet 80. The recyclestock is thus further converted at temperatures in the range of 1200 to1600 F. for a period of about l to 3 seconds. The con versionproductsfrom the recycle stock discharge into the uidized ,carrier mass in zone54 where a substantially lower temperature is maintained; hence, thedeep cracking eected in conduit 70 is arrested by the .quenchingactionof the tluidized carrier vin zone 54. The amount of recycle stock whichis .converted in .conduit 70 may be varied considerably. It is possibleand even commercially attractive to charge a heavy oil to primarycracking zone 54 through distributor 64 and to withdraw fromlthe recovery plantas end products only gasoline and vlighter" EXAMPLE l Anapparatus as illustrated in Figure 1 is charged with bauxite averaging160-mesh particle size. At an operatv ing gauge pressure of 400 p. s.i., the unit treats5, 000 barrels per day of an asphalt fractionobtained by the propane deasphalting of a 25% by weight Kuwait residuumand having the following characteristics:

Specific gravity Ramsbottom carbon residue,` wt. percent 27 Sulfur, wt;percent 6 The charge stock, preheated to about 550 F., is .injected intohydrogen-containing gas flowing through conduit 14 at a rate of about 38MM s. c. f. d. (million standard cubic feet per day). At the point ofoil injection, the combined stream has a temperature of about 1450" F.and this temperature decreases to about 1300 F. when the streamreachescyclone separator v26. The oil lis at conversion conditions forapproximately .1 sec. ond. The combined gas and oil stream has anaverage velocity of about-25 feet per second, a hydrogen partialpressure of about p. s. i. and a bauxite loading of about 1.5 pounds percubic foot ,of gas.

About 3.4 MM s. c. f. d. of oxygen (96% by volume purity) and 6.8 MM s.c. f. d. of steam respectively preheated to 300 F. and 1000 F. enterthrough conduit 32 to regenerate fouled bauxite at a temperature ofabout 1850 F. An additiona1'0.6 MM. s. c. f. l.d of steam is suppliedthrough tap 34. Wet steam is .introduced through distributor 40 tomaintain the .,uidizedmass above baille structure 38 at a temperature ofabout 1500 F.

The gasiform eluent from outlet 30 vis -processedin a recovery yplant toseparate out gasoline and lfuel oil .of the quality and in the quantityshown in the first column of Table I. The .gaseous residue of the euentyis scrubbed with a suitable solvent, e. g., diethanolarnine,

lto eliminate substantially all of the hydrogen sulde .and

carbon dioxide therein, and then .contacted -in the pres ence of addedsteam vwithan iron-chromium -waterggas shiftcatalyst at a temperature ofabout 775 F. to ytransform its carbon monoxide content to carbon dioxidehydrogen. After removal of water -vaporand carbon n f" dioxide nemth'esiiifted of theremainder.,` `This gasisrecycled to conduit 14 attherate of 38 MM s. c. f. dias aforesaid',while an ad-- ditional 19 MM s.c. i. d; is withdrawn from the system as an end product, namely,; a`fuel gas of high heating value. ip ,h i

` EXAMPLEEgZL--.

the regenerator in lieu of `steam and oxygen andsteam gas, Aresultinghydrogen-` i enriched gas ycontains about 75% by volume of hy drogen,and gaseous hydrocarbons whichY make up most In a run similar to thatofExample l, axrdlsused 1n Vals?":intuir ln` a run similar to that ofExample 3, none of the heavy end fraction is recycled to conduit 70 andsteam' is used in lieu of hydrogen-containing gas as the transport gasin conduit 70. The conversion products are given in the fourth column ofTable I. It is noteworthy that the gasoline yield `and quality areinferior to those of Example 3 and the product gas is lower in heatinvalue and quantity.

Table I Example.-. c 1 2 `a 4 Design .s 'Figi Figi i Flg.2 Flg.2

i p Transport Gas Steam Hi-Conf i Steam taining `gaizliierating Gas Air02+H1i0 01+Hi0 e 2 Gasoline. Barrels per Day 1,370 990 14,240 12,950,FueliOll. Barrels per Day. 945 685 830 i 4,140 i. FuelGas, MM s. c.1.1L.. 19.0 59.3 95.5 78.9

` 'Gasoline Quality:

`Octane Number, CFRR Clear- 09.2 98.9 90.2 88.0 i i i Sulfur, Wt.percent 0.31 1.70 0.41 V 0.45

" Fuel Oil Quality:

G 1.12 1.20 1.22 l'. p 4.7 12.4 8.a s f aso aaa soo '44o servesas thetransport-gas in'conduit 14. The quality` L It is evident from theexamples that the"process df and VLquantity ofthe conversion" productsare l shown in the second column ofTable I.V lIt shouldebe noted thatno-only is the yield of'liquid "precincts1 lower than; in Example l butalso the sulfur contents.` M A An apparatus" ais/Lil uitrated in Figure2 1s charged with liquid products have much higher thensalmesize bauxiteused in Examplefl. Operating i The charge stock is admixed with 23,000barrels per day of recycled middle distillate obtained from the`gasiform eluent leaving vessel 50 through outlet 80. The admixed oils,preheated to a temperature of 550 F., are charged through distributor64. About 21.9 MM s. c. f. d of oxygen (96% by volume purity) and 43.8MM s. c. f. d. of steam respectively preheated to about 300 F. and 1000F. are used to regenerate fouled carrier at a temperature of about 1850F. A heavy end fraction recovered from the gasiform eflluent exiting atoutlet 80 is recycled through line 82 and nozzle 84 at the rate of 8300barrels per day. Hydrogen-containing gas derived from the gasiformeiluent leaving vessel 50 through outlet 80 is passed through conduit 70at the rate of 84 MM s. c. f. d. and with a velocity of Vapproximately30 feet per second. The recycled oil is exposed in conduit 70 to amaximum temperature of about 1400 F., a hydrogen partial pressure of 120p. s. i., a bauxite loading of approximately 2 pounds per cubic foot ofgas and a residence time of nearly 1 second. The temperature in theprimary cracking zone 54 is 980 F.

The effluent leaving through outlet 80 is fractionated into gasoline,the aforesaid middle distillate (boiling range of 400 to 700 F.) theaforesaid heavy end fraction (boiling above 700 F.) and a gaseousresidue. All of the middle distillate is recycled to distributor 64. Theheavy end fraction is split into the 8300 barrels per day charged toline 82 and an additional 830 barrels per day which are withdrawn fromthe system as fuel In view of the various modifications of the inventionwhich will occur to those skilled in the art upon consideration of theforegoing disclosure without departing from the spirit or scope thereof,onlyv such limitations should be imposed as are indicated by theappended claims.

What is claimed is:

1. A process for the conversion of a heavy hydrocarbon oil having aRamsbottom carbon value: of at least about l0, which comprises injectingsaid oil into a rapidly moving gaseous stream containing hydrogen andhaving a velocity of at least about 10 feet per second and conveyingdispersed heated carrier particles from. a regeneration zone hereinafterspecified in substantially the same direction as that of said gaseousstream to yield a mixture having a hydrogen partial pressure of at leastabout 35 p. s. i. and a temperature in the range of about 1200 to 1600F., maintaining said mixture at temperatures in said range for not morethan about 3 seconds, separating said carrier particles from saidmixture, recovering converted hydrocarbons from the remaining gaseousportion of said mixture, treating the separated carrier particles in theaforesaid regeneration zone with oxygen and steam at a temperature aboveabout 1600 F. to reheat said separated carrier particles and to gasifycarbonaceous material deposited thereon by said oil thereby producinghydrogen-containing gases, recovering from said gases said gaseousstream containing hydrogen, and again conveying the reheated carrierparticles from the aforesaid regeneration zone in said gaseous streamcontaining hydrogen as aforesaid.

2. A process for converting heavy hydrocarbons boiling, above about 700F. and having a Ramsbottom car dief For stocks of high sulfur while thehydrocarbons are of the invention is con-V ducted at elevated pressure,to i maintain .the contemplated hydrogenr partial pressure. Inmostinstances,ioperation at a gauge pressurein therange of `1501011000 p. s.i. i is satisfactory; the preferredrange is 250 4to ;65O1p."s. i: Y

bonvalue ofaat least about 10 to lighthydrocarbons boil,- ing bel'ow'about'.4.00"` F., .which comprises conveying .heated carrier particles'rom'a regeneration zone heretemperatures in said range for not morethan about 3 seconds, separating said carrier particlesv from saidmixture, recovering'said lighthydrocarbonsfrom the-remaining gaseousportion of said mixture, treating the sep.- arated'carrier particles inthe aforesaid regenerationV zone with oxygen andsteamat a temperatureabove about I of"`about 1'200 to 1600 F., maintaining said mixture at16009" F. to rehe'at'r said'separatedfcarrier particles' and-V toygasifyearbonaceous` material. deposited thereon vby. said oil therebyproducing hydrogen-containing gases, recover.. ing; from said gases saidgaseous streamcontaining hydrogen, andy again conveyingl the reheatedcarrier particvlesj from the, aforesaid regeneration zone inAsaidlgaseous stream containing hydrogen as aforesaid.

3. The process of claim 1 wherein each. cubic, foot. of."

said gaseous stream containingv hydrogen conveysv not more than about 5pounds of said heated carrier. particles.

4. The process of claim. Lwhereinsaidcarrier particles arebauxiteparticles. f

5. The process of claim 2 wherein. eachcubic footofvv said gaseousstream. containing. hydrogen conveys not morethanabout 5..pounds, ofsaid heated carrier particles. 6. Thefprocess ofg clain1 2whereinsaid'mixture `has a hydrogen partial pressure of at least about 75 p.s..i.

7'.: A; processfor converting heavy ,hydrocarbons boil-1. ing aboveabout 700 F. and having a'Ramsbottom car-J1 bon .value oflat leastabout. 10 to light hydrocarbons boiling;.b'e1ow. about 400 F.,r whichcomprises conveyingheated'. carrier particlesfrom a regeneration zoneherevinafter specified-by suspension in a gaseous stream-conp taininghydrogen and having a velocity of at least about Ztleetrlltfr second sothat said carrier particles travelin substantially the, samerdirecti'onas lthatnof said' gast-OBS... stream, injectingsaidheavy'hyd'rfocarbons'into thesus-T pension o flsad carrier; particlesfinSaid gaseous .streamto form ar mixturefhavingga hydrogenpartialpressurein..

the range of about v to. 200 p..s. i. and a .temperature in therangeofaboutl'Orto 1F00".`V F.maintaining saidi Y mixturek attemperatures in said range fornot more than about 1 second, separatingsaid carrier particles from said mixture, recoveringfsaidlight@hydrocarbons from the remaining gaseousr portion off saidmixture,wreheat ing the separated.. carrier praticles in the aforesaid.re-v generation zone by reactingthe carbonaceous material deposited onsaid carrier particles by said heavy hydrocarbons with oxygen and steamat a temperature in the .range-of. about 1700 to 2000 F. therebyproducing hydrogen-containingv gases, recovering from said gases saidgaseous stream containing hydrogen, and again convey- 'ing thefreheatedcarrier particles from the aforesaid regeneration: zone in said gaseousstream containing hydrogen; as aforesaid.

8.The process of claim 7 wherein the reaction of the carbonaceousmaterial with oxygen and steam is conducted` by passing said oxygen andsteam upwardly through a` mass of said carrier particles with saidcarbonaceousmaterial deposited thereon under fluidizing conditions.

9. The' process of claim 7 wherein each cubic foot of said. gaseousstream containing hydrogen conveys not more. than-abouti; poundsfof.saidheated carrier: particles.,v

1:0...Tl1e process.. cfilamf/ wherein.said` heavy hydro5v carbons. have.ai. Ramsbottom. carbon,- value of .at least; y.

about. 1.5;y an d,. a sulfugf.- content-of' at 4least about 5%. by-Iweight.Y y v y y p y l v References Cited in Gle of this patent.A UNITEDSATES. PATENTS 2.411.104 Genti 255.7;680. u .Qdell June 19.195,112.60.63.862Y Keith .-Augzl 12, 1952;-- 2,687,992 Leffer ...,Augv4 31,`1954 My 24. rafts,

Beckberger Mai-..13, 1956 .l

1. A PROCESS FOR THE CONVERSION OF A HEAVY HYDROCARBON OIL HAVING ARAMSBOTTOM CARBON VALUE OF AT LEAST ABOUT 10, WHICH COMPRISES INJECTINGSAID OIL INTO A RAPIDLY MOVING GASEOUS STREAM CONTAINING HYDROGEN ANDHAVING A VELOCITY OF AT LEAST ABOUT 10 FEET PER SECOND AND CONVEYINGDISPERSED HEATED CARRIER PARTICLES FROM A REGENERATION ZONE HEREINAFTERSPECIFIED IN SUBSTANTIALLY THE SAME DIRECTION AS THAT OF SAID GASEOUSSTREAM TO YIELD A MIXTURE HAVING A HYDROGEN PARTIAL PRESSURE OF AT LEASTABOUT 35 P. S. I. AND A TEMPERATURE IN THE RANGE OF ABOUT 1200 TO1600*F., MAINTAINING SAID MIXTURE AT TEMPERATURES IN SAID RANGE FOR NOTMORE THAN ABOUT 3 SECONDS, SEPARATING SAID CARRIER PARTICLES FROM SAIDMIXTURE, RECOVERING CONVERTED HYDROCARBONS FROM THE REMAINING GASEOUSPORTION OF SAID MIXTURE, TREATING THE SEPARATED CARRIER PARTICLES IN THEAFORESAID REGENERATION ZONE WITH OXYGEN AND STREAM AT A TEMPERATUREABOVE ABOUT 1600*F. TO REHEAT SAID SEPARATED CARRIER PARTICLES AND TOGASIFY CARBONACEOUS MATERIAL DEPOSITED THEREON BY SAID OIL THEREBYPRODUCING HYDROGEN-CONTAINING GASES, RECOVERING FROM SAID GASES SAIDGASEOUS STREAM CONTAINING HYDROGEN, AND AGAIN CONVEYING THE REHEATEDCARRIER PARTICLES FROM THE AFORESAID REGENERATION ZONE IN SAID GASEOUSSTREAM CONTAINING HYDROGEN AS AFORESAID.